1956 Mercury Temperature Sending Unit

[lalkie]

I have a 56 Montclair convertible. I am having trouble finding a temperature sending unit that works. When I ground the gauge wire the gauge goes to H.
I purchased a sending unit from NAPA Part #ts6464. Does anyone have a part number for one that they have purchased and that actually works? Larry

[dmsfrr]

The one shown at this link with that part number looks like a '57+ sensor and is labeled as a 'Fan Switch',. image 1.
https://www.napaonline.com/en/search...464&referer=v2

The earlier Temp sensors are larger, with 3/8 'pipe' thread. The smaller is 1/4 NPT. Example photo 2.

An original '56 Temp sensor is a one-year-only part. A shop that has obsolete Ford parts may have one.
Or one of the '55/'57 T-Bird suppliers. Example...
https://www.classictbird.com/Temp-Se...ctinfo/10884B/
.

[KULTULZ]

The problem here is that the 56 SWITCH was a one year deal.

If you can't find one NOS ($$$) (B6C 10884-A) then you will have to use off-shore.

EDIT - CORRECTION -

The PN above has been corrected - B6A 10884-A

Don't Ask - Bad Night ...

[lalkie]

The one I Bought at NAPA a few years ago has the 3/8 thread and looks like the original. They have apparently changed to a different style. The one KULYULZ mentioned would probably work except for the electrical connection. Mine has a threaded post. Looks like I spend the money or put in an aftermarket one. Thanks for the response. Larry

[lalkie]

Does anyone know the ohm readings for the 56 Merc temperature switch?

[KULTULZ]

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Originally Posted by lalkie

The one I Bought at NAPA a few years ago has the 3/8 thread and looks like the original. They have apparently changed to a different style. The one KULYULZ mentioned would probably work except for the electrical connection. Mine has a threaded post. Looks like I spend the money or put in an aftermarket one. Thanks for the response. Larry

Originally Posted by lalkie

Does anyone know the ohm readings for the 56 Merc temperature switch?

Do you have a 56 MERC SHOP MANUAL? There should be a DIAGNOSTIC sequence given for complete diagnosis of the whole system as well as the OHM rating of the switch.

1956 FORD-LINCMERC-LT was unique one year only.

I see where DENNIS CARPENTER and others are listing an aftermarket MADE IN USA supposedly.

OEM SWITCH PHOTO -



As mentioned previously, if the one NAPA gave you is a one pin, it is for a 57. Its measurements are 3-8in x 18.

[rotorwrench]

The 1956 type in the photographs appears to be the King Seeley type. With this being the first year of 12-volts, they must have decided to make a change for the next year. All previous units were set for 6-volt clear back to 1939 or so. With a change in 1957 to a different type altogether then this makes for a low production part for certain. Reproduction and aftermarket units are likely out there but sources are probably limited.

Flathead V8s had to use two units due to separate cooling systems in the block but only one gave temperature indications. The other unit was just a temperature sensitive switch that gave a full hot condition if it reached the set temperature.

If you try to measure ohms, all you will read is the heating coil element inside the sending unit. These units directly vary the current flow to the indicator in the dash rather than use a variable resistor like some units do in later years and from other auto manufacturers.

[dmsfrr]

Originally Posted by lalkie

The one I Bought at NAPA a few years ago has the 3/8 thread and looks like the original. ... Mine has a threaded post. Looks like I spend the money or put in an aftermarket one. Thanks for the response. Larry

If it looks like the larger version but has a threaded post it may or may not work correctly.
Since you already have it you might as well give it a try???

Originally Posted by rotorwrench

The 1956 type in the photographs appears to be the King Seeley type. ...

If you try to measure ohms, all you will read is the heating coil element inside the sending unit. These units directly vary the current flow to the indicator in the dash rather than use a variable resistor like some units do in later years and from other auto manufacturers.

Yes, what he said. ^^^ The '56 and earlier oem sensor units use bi-metal switching contacts.
.

[miker98038]

Here’s an old post on king seely, read to the end where he makes a correction. Many other makes used them, I’ve found a lot of more info on other sites than Ford. Bottom line, a 56 ford sender probably works, and the Thunderbird suppliers have them, as stated above. But it’s good to know what you’re working on and how you can calibrate them.

http://forums.y-blocksforever.com/Topic22135-1.aspx

[lalkie]

Thanks guys. The posts are helpful. Larry